There's a few factors to consider when selecting a winch for urban logging. What size you need will greatly depend on the size of logs you're going after and potentially planning for even larger logs than you're expecting now. The short answer is to buy bigger than you need and not worry about it as much. The cost difference between the different capacities isn't very large. The only downside is as the capacity increases the winch gets heavier but if you're not moving it around and leaving it bolted to your trailer, this isn't really an issue.
I got a call about a walnut tree that was coming down and this was a really fun outing. The loading was just a bit challenging which made it more interesting than just driving up to a pile of logs. You know how I love a good adventure!